Cell Theory, Cell Biology, and Transport - Vocabulary Flashcards

Vocabulary flashcards covering key terms from the lecture notes on cell theory, cell structure, cell division, prokaryotes/eukaryotes, plant/animal cell specialization, and membrane transport.

Zacharias Jansen

Dutch eyeglass maker who is credited with inventing the very first microscope (1590).

Robert Hooke

Early microscopist who observed cork cells and coined the term ‘cells’ (1665).

Anton van Leeuwenhoek

Inventor of a simple, handmade microscope; observed living microorganisms in pond water, calling them animalcules (1674).

Matthias Schleiden

German botanist who stated that all plants are made of cells (1838).

Theodor Schwann

Scientist who stated that all animals are made of cells (1839).

Rudolf Virchrow

Stated that cells come from preexisting cells via cell division (1855).

Cell Theory

Foundational idea that all living things are made of cells; cells are the basic unit of structure and function. (Contributors include Hooke, Schleiden, Schwann, and Virchow.)

Modern Cell Theory

Adds that cells contain genetic material passed during cell division, are similar in structure and chemistry, and energy flow occurs within cells.

Cell membrane

Thin, double layer of phospholipids that surrounds the cell; acts as a selective barrier and regulates substance passage.

Cell wall

Rigid outer layer in plants, fungi, and bacteria that provides support and protection.

Nucleus

Control center of the cell; contains DNA and is enclosed by a double membrane with pores.

Nucleolus

Structure inside the nucleus that produces ribosomes.

Ribosome

Molecular machine where protein synthesis occurs; made of RNA and protein.

Mitochondria

Powerhouse of the cell; produces chemical energy (ATP) via cellular respiration.

Endoplasmic reticulum (ER)

Network of membranous tubules; Rough ER has ribosomes and synthesizes proteins, Smooth ER makes lipids and detoxifies.

Golgi apparatus

Stack of flattened membranes that modifies, sorts, and ships proteins and lipids.

Lysosome

Organelle containing digestive enzymes that break down waste and damaged parts.

Chloroplast

Plant cell organelle that carries out photosynthesis; contains chlorophyll.

Vacuole

Large membrane-bound storage sac; stores water, nutrients, and waste.

Cytoskeleton

Network of protein filaments that provides shape, support, and transport within the cell.

Cytoplasm

Gel-like fluid inside the cell that houses organelles and facilitates chemical reactions.

Vesicles

Small membrane-bound sacs that transport materials inside the cell.

Centrioles

Animal cell structures that organize spindle fibers during cell division.

Centrosome

Region near the nucleus that organizes microtubules during cell division.

Prokaryotic

Unicellular organisms lacking a nucleus and membrane-bound organelles (e.g., bacteria, archaea).

Eukaryotic

Organisms with cells that contain a nucleus and membrane-bound organelles; includes plants, animals, fungi, and protists.

Nucleoid

Region in prokaryotes where DNA is located, not enclosed by a membrane.

Cytosol

Fluid portion of the cytoplasm containing dissolved molecules.

Cytoplasm

Gel-like substance inside the cell where metabolic reactions occur.

Archaea

Group of single-celled prokaryotes with distinct biochemistry; often extremophiles.

Bacteria

Single-celled prokaryotes; thrive in diverse environments.

Plant cell

Eukaryotic cell type with chloroplasts, a cell wall, and a large central vacuole.

Animal cell

Eukaryotic cell type lacking a cell wall and chloroplasts; contains organelles similar to other eukaryotic cells.

Unicellular

Organisms consisting of a single cell.

Multicellular

Organisms made up of many cells that often differentiate.

Red blood cell (RBC)

Blood cell adapted to carry oxygen; lacks a nucleus in many species and contains hemoglobin.

White blood cell (WBC)

Immune system cell that defends against pathogens; varied shapes and functions.

Sperm cell

Male gamete; elongated with a long tail for movement; carries genetic material.

Egg cell

Female gamete; large and nutrient-rich; carries genetic material.

Nerve cell (neuron)

Cell that transmits nerve impulses; has a long axon and branched dendrites.

Muscle cell

Cell specialized for contraction; elongated with many mitochondria.

Cell differentiation

Process by which cells become specialized in structure and function.

Guard cell

Plant cell that regulates stomatal opening and transpiration.

Root hair cell

Plant cell with a long, thin shape to maximize water and mineral absorption.

Photosynthetic cell

Plant cell specialized for photosynthesis; numerous chloroplasts.

Xylem vessel

Plant cell tube that transports water and minerals; lignified secondary walls provide support.

Interphase

Cell cycle phase when the cell grows and DNA is replicated in preparation for division.

G1 phase

First gap phase; cell grows and synthesizes proteins and organelles.

S phase

DNA synthesis phase; genetic material is replicated.

G2 phase

Second gap phase; cell grows and prepares for mitosis; ATP and tubulin are synthesized.

G0 phase

Non-dividing resting state; cell performs normal functions without division.

Mitosis

Nuclear division producing two genetically identical diploid daughter cells.

Prophase

Chromosomes condense, nuclear envelope breaks down, spindle forms.

Metaphase

Chromosomes align at the cell's equatorial plane; spindle fibers attach to kinetochores.

Anaphase

Sister chromatids separate and move to opposite poles; cell elongates.

Telophase

Chromosomes arrive at poles, decondense, nuclear envelope reforms.

Cytokinesis

Division of the cytoplasm forming two separate daughter cells.

Meiosis

Cell division producing four genetically unique haploid gametes.

Crossing over

Exchange of genetic material between homologous chromosomes during meiosis I.

Homologous chromosomes

Pair of chromosomes containing same genes; can exchange during crossing over.

Sister chromatids

Identical copies of a chromosome held at the centromere until separation.

Chiasmata

Points where crossing over occurs between homologous chromosomes.

Trisomy

Having an extra chromosome (2n+1); can cause disorders like Down syndrome.

Monosomy

Lack of a chromosome (2n-1); e.g., Turner syndrome (Monosomy X).

Diploid

Cell with two complete sets of chromosomes (2n).

Haploid

Cell with a single set of chromosomes (n); produced by meiosis.

Chromosome

Structure composed of DNA and proteins that carries genetic information.

DNA replication

Process of copying the DNA so identical genetic material is passed to daughter cells.

Chromatid

One of the two identical halves of a replicated chromosome.

Cilia

Hair-like organelles that can be non-motile (sensory) or motile (movement) for cell propulsion.

Flagella

Long, whip-like organelle made of protein for cell movement.

Vesicle transport

Movement of materials in membrane-bound sacs within or outside the cell.

Endocytosis

Cell takes in material by engulfing it with the membrane.

Phagocytosis

Endocytosis of large particles; often called 'cell eating'.

Pinocytosis

Endocytosis of fluids and small molecules; often called 'cell drinking'.

Receptor-mediated endocytosis

Endocytosis initiated when ligands bind to specific receptors before internalization.

Exocytosis

Process by which vesicles fuse with the plasma membrane to release contents outside the cell.

Diffusion

Passive movement of small nonpolar molecules from high to low concentration.

Osmosis

Diffusion of water across a semi-permeable membrane from low solute to high solute.

Facilitated diffusion

Passive transport that uses channel or carrier proteins to move substances.

Active transport

Movement of substances against their concentration gradient requiring energy (ATP).

Primary active transport

Direct use of ATP by a membrane transporter to move substances.

Secondary active transport

Uses energy from ion gradients to transport substances (via symport/antiport).

Symporter

Transporter that moves two substances in the same direction.

Antiporter

Transporter that moves two substances in opposite directions.